| 摘要 |
<p>The prodn. of ethylene glycol involves an initial stage (1) in which formaldehyde is contacted with a gas contg. CO and H2, in the presence of HF, so that CO is removed from the gas and (di)glycolic acid is produced. This acid reacts, in stage (2), with ethylene glycol and/or diethylene glycol, to give the corresp. glycolates. In stage (3) the residual CO and HD are extracted from the gas from stage (1) to give a gas with high H2 content which is contacted, in stage (4), with the glycolate(s), giving (di)ethylene glycol, a part of which is recycled to stage (2) to maintain a molar excess of glycol during the esterification. This process gives high yields of ethylene glycol.</p> |
